Buying power is a ceiling, not a target
Buying power answers one narrow question: what's the biggest position my collateral can control? The maths is simple — balance × leverage — but the number is easy to misread. $1,000 at 20x shows $20,000 of buying power, and it's tempting to treat that as your trade size. It isn't. It's the absolute maximum, the point where every dollar of margin is committed, there's no cushion to add, and a ~5% move against you is fatal. The useful version of this calculator is the "buying power to use" field: dial it down to the fraction you'd actually risk on one idea and read the sane position size that falls out.
The table shows the same balance across a ladder of leverage. Notice that the buying power column and the "move to liquidation" column move in opposite directions — every extra turn of leverage buys a bigger position and a closer liquidation price in the same step. That trade-off, not the headline notional, is the thing to weigh. Once you've picked a position size here, size it properly by risk with the position size calculator, confirm the exact level with the liquidation calculator, and if you started from a target position instead, flip to the required leverage calculator.
How to use it
1. Pick long or short.
2. Enter your account balance and the maximum leverage you'll allow yourself.
3. Add the entry price and, if you plan to run more than one trade, how many positions you'll split the account into.
4. Set "buying power to use" to the share you'd actually deploy, and read the position size, coin quantity and margin per position.
Common mistakes
Treating buying power as the plan. The max position is the most dangerous one — it leaves zero room for the trade to move. Forgetting fees and the maintenance buffer. Opening right at the ceiling means you're liquidated a hair before your margin actually reaches zero. Splitting the account but sizing each trade to full buying power. If you want five positions, each gets a fifth of the margin, not the whole thing. Confusing more buying power with more money. Leverage multiplies the position, not your balance — the risk scales up with it.
FAQ
Is buying power the same as my balance? No — balance is your real money (the margin). Buying power is that balance multiplied by leverage: the exposure you can open with it. Losses and liquidation still hit your balance, not the buying-power figure.
How much of my buying power should one trade use? There's no fixed rule, but committing everything to one position is how accounts get wiped by ordinary volatility. Many traders keep single-trade exposure well below the maximum and size by a fixed risk percentage instead.
Why is the coin quantity what matters at execution? Exchanges fill orders in coin units, not dollars. Buying power ÷ entry price gives the quantity you'd actually place — handy for setting the order size directly.